ELECTROMAGNETIC-WAVE ABSORBING SHEET
An electromagnetic-wave absorbing sheet is realized which can favorably absorb electromagnetic waves with a high frequency in or above a millimeter-wave band, and has sufficient elasticity. The electromagnetic-wave absorbing sheet includes: an electromagnetic-wave absorbing layer 1 that includes a particulate electromagnetic-wave absorbing material 1 a and a rubber binder 1 b ; and a dielectric layer 2 arranged on a back surface of the electromagnetic-wave absorbing layer. The electromagnetic-wave absorbing material is a magnetic iron oxide that magnetically resonates in a frequency band that is at least a millimeter-wave band. The dielectric layer is non-magnetic and has flexibility, a real part of a complex relative permittivity of the dielectric layer is 2 or more and 6 or less, and the dielectric layer has a thickness of 10 μm or more and 100 μm or less.
1 . An electromagnetic-wave absorbing sheet comprising:
an electromagnetic-wave absorbing layer that includes a particulate electromagnetic-wave absorbing material and a rubber binder; and
a dielectric layer arranged on a back surface of the electromagnetic-wave absorbing layer,
wherein the electromagnetic-wave absorbing material is a magnetic iron oxide that magnetically resonates in a frequency band in or above a millimeter-wave band, and
the dielectric layer is non-magnetic and has flexibility, a real part of a complex relative permittivity of the dielectric layer is 2 or more and 6 or less, and the dielectric layer has a thickness of 10 μm or more and 100 μm or less.
2 . The electromagnetic-wave absorbing sheet according to claim 1 , wherein a reflective layer that reflects electromagnetic waves that have passed through the electromagnetic-wave absorbing layer and the dielectric layer is formed on a back surface of the dielectric layer.
3 . The electromagnetic-wave absorbing sheet according to claim 1 , wherein the electromagnetic-wave absorbing material is epsilon iron oxide or strontium ferrite.
4 . The electromagnetic-wave absorbing sheet according to claim 1 , wherein the electromagnetic-wave absorbing material is epsilon iron oxide, and a portion of Fe sites of the epsilon iron oxide are substituted with trivalent metal atoms.
5 . The electromagnetic-wave absorbing sheet according to claim 1 , wherein the dielectric layer is formed as a stacked body with two or more layers.
6 . The electromagnetic-wave absorbing sheet according to claim 1 , wherein the dielectric layer has adhesiveness.